August 21, 2017

Effectiveness of Veterinarian-Administered Otic Gel in Dogs with Otitis Externa

Compared with standard owner-administered otic therapy, researchers sought to determine whether a veterinarian-administered otic gel leads to higher quality of life scores for dogs with otitis externa and their owners.
By JoAnna Pendergrass, DVM
Canine otitis externa (OE) is a common disease in veterinary medicine. It can negatively affect a dog’s quality of life (QoL), causing stress during ear manipulation and disrupting sleep and play patterns. In addition, dog owners can become frustrated if their dog has chronic OE or is recalcitrant during treatment. Prolonged OE treatment can also negatively affect QoL, reducing treatment compliance and possibly compromising the dog-owner relationship.

A Veterinary Dermatology article recently reported that, compared with standard owner-administered otic therapy, a veterinarian-administered otic gel has equal efficacy and provides better QoL for dogs with OE and their owners.

Osurnia (florfenicol terbinafine betamethasone acetate) is an otic gel representing an option for dog owners struggling with at-home OE treatment. Indicated for acute OE, it provides weeks-long antibacterial and antimycotic activity. Recommended administration is by a veterinarian.

Because clinical improvement with OE treatment does not necessarily improve QoL for dogs and their owners, the current study simultaneously assessed clinical parameters and QoL.

Treatment and Assessment
Researchers evaluated 50 pet dogs with acute or chronic OE over 28 days. Dogs first received ear cleanings with a cerumenolytic solution and were equally randomized into treatment groups:
  • Group A: Two veterinarian-administered applications of Osurnia, 1 week apart (days 0 and 7)
  • Group B: Once-daily application of otic drops and twice-weekly ear cleanings by owner from day 0–14
Dogs were assessed on days 0 (baseline), 7, 14, and 28. Clinical OE signs were scored using the OTI-3 scale. Exudate cytology scores considered the presence of rods, cocci, yeast, and neutrophils. Pruritus scores were determined using a Visual Analog Scale (VAS). All scores indicated severity level.

At each visit, owners completed a questionnaire to report QoL of their dogs (QoL1) and themselves (QoL2). Global treatment efficacy was assessed on day 28.

OE was unilateral in 15 dogs and bilateral in 35 dogs. Also, it was acute in 23 dogs and chronic in 27 dogs.

Overall, all parameters improved for both treatment groups. Within-parameter differences in improvement, though, were observed.

In group A, QoL1 and QoL2 improved significantly from baseline at all time points. In group B, significant improvement was not observed until day 14 for QoL1 and day 28 for QoL2, potentially reflecting the burden of owner-administered treatment.

At all time points, percentage improvement of QoL1 and QoL2 from baseline was greater in group A than group B.

Although pruritus improved significantly at all time points for most dogs, a few dogs in each group remained abnormally pruritic at study’s end; uncontrolled allergic disease may have been the cause, researchers believed. Percentage improvement was significantly greater in group A only at day 7, indicating similar treatment efficacy between groups and the gel’s rapid activity.

OTI-3 and Cytology
OTI-3 and cytology scores significantly improved from baseline at all time points for both groups. Percentage improvement of OTI-3 scores was greater in group A than in group B through study’s end. In contrast, percentage improvement of cytology scores was significantly greater in group A only on days 7 and 14, again indicating similar treatment efficacy and the gel’s rapid activity.

Global Efficacy
Owners and veterinarians considered treatment efficacy to be good or excellent for most dogs in both treatment groups.

Looking Forward
This study’s findings have important implications for owner satisfaction and treatment compliance for dogs with chronic and difficult-to-treat OE. For future OE treatment studies, researchers suggested including the primary cause of allergic disease in the analysis.

Dr. Pendergrass received her Doctor of Veterinary Medicine degree from the Virginia-Maryland College of Veterinary Medicine. Following veterinary school, she completed a postdoctoral fellowship at Emory University’s Yerkes National Primate Research Center. Dr. Pendergrass is the founder and owner of JPen Communications, a medical communications company.

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